Review on terahertz metamaterial absorbers

Absorbers are devices that internally consume electromagnetic waves to partially or completely attenuate them. The basic idea is to absorb electromagnetic radiation by resonating the intended surface with the incident electromagnetic waves. This article focuses on the development of the absorber. (from single-band to multi-band, narrow to broadband, non-tunable to tunable, and so on). The basic absorption principle of the current popular and excellent metamaterial graphene absorber is provided, as is the theoretical explanation of impedance matching and how to attain critical performance metrics like tunability, as well as prospects for terahertz（THz） absorber applications. Finally, numerous innovative absorbers are shown as examples, providing new ideas for future researchers.